Method and apparatus for draining liquid carrying ducts which transport liquid to and from liquid holding containers

ABSTRACT

A trough-like implement having a wall member or members extending forward at one end and along the sides to define a substantially continuous sealing lip around the two sides and one end, is used to drain pipe or ducts which carry liquid to and from a liquid holding container, such as a swimming pool, without materially reducing the liquid level of the container. The trough-like implement is lowered into the pool with the sealing lip in engagement with a container wall and surrounding a duct port so that the area inside the trough-like member is effectively isolated from the main body of liquid in the container. The liquid inside the trough-like implement is then removed, as by bailing or siphoning, to a level below the duct port, the duct is next drained and sealed and the implement is then removed to let the liquid in the container seek its own level. The process is repeated for each duct which is to be drained.

United States Patent 1 1111 3,858,597

Pramenko 1 Jan. 7, 1975 4] METHOD AND APPARATUS FOR [57] ABSTRACTDRAINING LIQUID CARRYING DUCTS WHICH TRANSPORT LIQUID TO AND FROM LIQUIDHOLDING CONTAINERS [76] Inventor: George M. Pramenko, 521

University Ave., Missoula, Mont. 59801 [22] Filed: Dec. 28, 1973 [21]Appl. No.: 429,275

[52] US. Cl 137/1, 4/.172.17, 137/590 [51] Int. Cl Et14h 3/16 [58] Fieldof Search 137/1, 15, 215, 216,590,

Primary ExaminerAlan Cohan Attorney, Agent, or FirmGregg, Hendricson &Caplan A trough-like implement having a wall member or members extendingforward at one end and along the sides to define a substantiallycontinuous sealing lip around the two sides and one end, is used todrain pipe or ducts which carry liquid to and from a liquid holdingcontainer, such as a swimming pool, without materially reducing theliquid level of the container. The trough-like implement is lowered intothe pool with the sealing lip in engagement with a container wall andsurrounding a duct port so that the area inside the trough-like memberis effectively isolated from the main body of liquid in the container.The liquid inside the trough-like implement is then removed. as bybailing or siphoning, to a level below the duct port. the duct is nextdrained and sealed and the implement is then removed to let the liquidin the container seek its own level. The process is repeated f0 eachduct which is to be drained.

6 Claims, 2 Drawing Figures METHOD AND APPARATUS FOR DRAINING LIQUIDCARRYING DUCTS WHICH TRANSPORT LIQUID TO AND FROM LIQUID HOLDINGCONTAINERS BACKGROUND OF THE INVENTION In Winterizing swimming pools, ithas been found that damage to the pool is minimized if water ismaintained at essentially the normal level throughout the cold weather.However, it is necessary to drain inlet and drainage pipes that are nearenough the surface of the ground to freeze during the cold weather.Should liquid in the pipes (ducts or conduits) be frozen, the pipes willmost likely be broken and require replacement.

This particular application, i.e., Winterizing swimming pools, inspiredthe present invention, therefore, the following description is made withreference to this use. However, it will be understood that the inventionhas many other uses.

In order to drain near-surface inlet and outlet pipes for swimmingpools, it has been the practice to drain the pool until ports are abovethe level of'the water in the pool. The pipes are then cleared of waterand sealed and the pool then refilled to avoid winter damage. Pooldrainage and refill operations are time consuming, wasteful of water andexpensive.

OBJECTS AND SUMMARY OF THE INVENTION It is an object of this inventionto provide a means of isolating and draining ducts or pipes which areopen to and have ports beneath the liquid level of a main body of liquidwithout reducing the liquid level materially.

Another object of the invention is to provide means and method forperforming the above function simply and inexpensively and in a minimumamount of time.

In carrying out the invention, a body of liquid around an entry or exitport of a container is sealed off or isolated from the main body ofliquid in the container by providing a trough-like implement having wallportions extending forward along the sides and bottom, thereby to form acontinuous sealing lip around the sides and bottom, and inserting theimplement in the container with the sealing lip snug against thecontainer wall around a port and removing liquid from the sealed offarea (inside the troughdike implement) until the port is exposed abovethe liquid level, draining and sealing the pipe or duct whichcommunicates with the container at the port and removing the trough-likeimplement to allow liquid in the container to seek its own level in theport area. The process is repeated for each port for a conduit to bedrained.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of oneembodiment of a trough-like implement used in carrying out the methoddescribed, and

FIG. 2 is a broken away cross sectional view showing a central verticalsection of the implement of FIG. 1 positioned around a conduit port andagainst a swimming pool wall as contemplated for carrying out the methoddescribed.

DESCRIPTION OF PREFERRED EMBODIMENTS For an understanding of theconfiguration of the trough-like implement used in the drainingprocedure, reference may be had to both figures of the drawing.Functionally, the purpose of the implement 10 is to entrap and isolate arelatively small body of liquid (water) 12 from a larger body 14. Inorder to form such a closure and still provide an open area at the topofthe implement 10 to allow access to the entrapped water 12 for removaland also a working area inside the implement, the implement 10 is madegenerally U-shaped with a back wall 16 forming the bottom of the U andside walls (18 and 20) extending inwardly defining the legs of the U.

lnthe embodiment illustrated, the side walls 18 and 20 extend forward atright angles relative to the back wall 16. The trough-like implement 10is closed at the lower end by sloping the lower portion 22 of the backwall inwardly and providing a forward bent portion 24 which isperpendicular to the bottom of the U" 16 and both side walls 18 and 20.The forward extension of the back wall 16 is such that the side walls 18and 20 and the lowerportion 24 of the back wall 16 terminate insubstantially a plane.

A continuous sealing lip '26 is provided around the open side of theimplement l0 defined by the planar inner extremeties of the side andback walls 18, 20 and 16 respectively. As illustrated, the sealing lip26 is formed by turning the inner extremeties of each of the walls (16,18 and 20) inward to form an essentially planar rim. Sealing propertiesof the sealing lip 26 is improved by providing a resilient materialthereon (indicated in the drawing only by the shading). In practice asponge rubber strip A inch thick by '94. inch wide is glued around thesurface of the sealing lip 26-and a inch plastic tape is applied to thesurface of the rubber strip.

For an understanding of how the implement 10 just described is used inthe Winterizing process for swimming pools, reference should be made toFIG. 2 of the drawing. A duct or pipe 28 which normally contains wateris located below the normal water level of the main body of water 14 inthe pool, extends through the wall 30 of the pool and has a port 32which is open to the pool. Assume that the pipe 28 is less than a footunder the surface of the earth 34 and therefore is in danger of freezingin the winter.

In order to isolate the pipe port 32 along with a smaller (entrapped)body of water 12 from the main body of water 14, the trough-likeimplement 10 is low ered, closed end first, into the pool, with thesealing lip 26 against the pool wall 30. The fact that the lower end ofthe implement 10 has its back wall 16 tapered (along the portion 22)makes it easier to lower the implement into the pool. Immediately afterthe implement 10 is lowered into the pool, the entrapped water 12 is atthe same level as the main body 14 (not shown). With the sealing lip 26of the implement snug against the side 30 of the pool and surroundingthe port 32, the entrapped body of water 12 is removed, as by bailing orsiphoning, until its level is below the port 32. Note thatas the wateris removed from inside the implement l0, pressure from the main body ofwater 14 increases the sealing action of the sealing lip 26 against thepool wall due to increased differential pressure.

Once the level of the isolated body of water 12 inside the implement 10is below the port 32, the pipe 26 is drained and sealed, as by pluggingthe port 32. In view of the pressure differential between the outsideand inside of the implement 10, it probably will not be possible ordesirable simply to pull it out of the water.

Therefore, it is normally necessary to equalize the external andinternal pressure by refilling the isolated area inside the troughbefore removing the implement 10. For every duct or pipe which must bedrained the process just described is repeated.

The trough-like implement illustrated has proven highly satisfactory.The implement, however, is not limited to the particular structure shownsince the principle employed is the important thing. Many otherstructures can be envisioned which are obviously within the teachingsset forth. Further, the implement illustrated has been made of bothgalvanized and stainless steel. Both of these materials are imminentlysatisfactory but, again, many other materials may be employed withoutdeparting from the present teachings. For example, the trough-likeimplement may be cast or molded in a single piece of, for example,plastic in a form which could be considered a single wall which has agenerally arcuate back extending forward at the sides and bottom to forma sealing lip which corresponds to that (26) of the implement 10 shown.It should be equally apparent that size of the implement is not criticalto the principles taught and depends to a certain extent upon theparticular use. It has been found, however, that a good wall seal ismade for swimming pools with relatively rough walls when the width ofthe implement 10 is about eighteen inches. Sufficient working room isprovided between the pool wall and the back 16 of the trough-likeimplement 10 when the dimension from sealing lip 26 .to back 16 is abouta foot. For most pools, a length of about 38 inches is highlysatisfactory especially since it is highly unlikely that pipes two ormore feet underground will freeze. An implement 10 of these dimensionsentraps approximately 8 gallons of liquid.

The structures and steps of the invention have been shown and describedin preferred form and order only, and by way of example. Many variationsmay be made in the invention without departing from the true spirit andscope. It is understood, therefore, that the invention is not limited toany specific form, steps or sequence of steps except insofar as they arenot contemplated by appended claims.

What is claimed is: i

l. The method of draining a liquid carrying duct which communicates witha container confining a main body of liquid in a way to permit drainageof the said duct without materially reducing the level of said main bodyof liquid including the steps of inserting an isolat ing means in saidmain body of liquid around a duct to be drained-thereby isolating a bodyof liquid around the said duct from the main body of liquid, removingthe liquid in the said isolated area to a level below the said duct anddraining the liquid from the said duct, sealing the said duct andremoving said isolating means thereby allowing said main body of waterto seek its level relative to the said duct.

2. The method of draining a liquid carrying duct which communicates witha container confining a main body of liquid as defined in claim 1wherein removing the liquid in the said isolated area to a level belowthe said duct and draining the liquid from the said duct is carried outin two steps; viz., first removing the liquid in the said isolated areato a level below the said duct and next, draining the liquid from thesaid duct.

3. The method of draining a plurality of liquid carrying ducts whichindependently communicate with a container confining a main body ofliquid wherein the method as defined in claim 1 is independently carriedout for each said independent duct.

4. The method of draining a plurality of liquid carrying ducts whichindependently communicate with a container confining a main body ofliquid wherein the method as defined in claim 2 is independently carriedout for each said independent duct.

5. The method of draining a liquid carrying duct which communicates witha container confining a main body of liquid as defined in claim 2wherein the said step of removing said isolating means is carried out intwo steps, viz., refilling the said isolated area to a levelsubstantially the level of the said main body of liquid and thenremoving the said isolating means.

6. The method of claim 1 wherein said container is a swimming pool.

1. The method of draining a liquid carrying duct which communicates witha container confining a main body of liquid in a way to permit drainageof the said duct without materially reducing the level of said main bodyof liquid including the steps of inserting an isolating means in saidmain body of liquid around a duct to be drained thereby isolating a bodyof liquid around the said duct from the main body of liquid, removingthe liquid in the said isolated area to a level below the said duct anddraining the liquid from the said duct, sealing the said duct andremoving said isolating means thereby allowing said main body of waterto seek its level relative to the said duct.
 2. The method of draining aliquid carrying duct which communicates with a container confining amain body of liquid as defined in claim 1 wherein removing the liquid inthe said isolated area to a level below the said duct and draining theliquid from the said duct is carried out in two steps; viz., firstremoving the liquid in the said isolated area to a level below the saidduct and next, draining the liquid from the said duct.
 3. The method ofdraining a plurality of liquid carrying ducts which independentlycommunicate with a container confining a main body of liquid wherein themethod as defined in claim 1 is independently carried out for each saidindependent duct.
 4. The method of draining a plurality of liquidcarrying ducts which independently communicate with a containerconfining a main body of liquid wherein the method as defined in claim 2is independently carried out for each said independent duct.
 5. Themethod of draining a liquid carrying duct which communicates with acontainer confining a main body of liquid as defined in claim 2 whereinthe said step of removing said isolAting means is carried out in twosteps, viz., refilling the said isolated area to a level substantiallythe level of the said main body of liquid and then removing the saidisolating means.
 6. The method of claim 1 wherein said container is aswimming pool.